Load-sensing vehicle lift

Abstract

Conventional vehicle lifts typically operate at a standard speed that is statically configured for the system, which may result in vehicles that are below the weight rating for the lift being raised at the standard speed while the lift motor is capable of safely raising at greater speeds. A set of lift controls may be configured to determine the load on the motor by a vehicle of an unknown weight during operation at a standard lift speed and use such information to determine a potential speed that the motor may raise the vehicle at while staying within safe operational levels for the motor. One or more of a magnitude of electrical power drawn, a pressure generated by a hydraulic lifting, or a sensed vehicle weight may be used to provide an indication of load on the motor and/or a higher potential speed.

The invention claimed is: 
     
       1. A lift system, comprising:
 a lift post, wherein the lift post comprises a lower portion and an upper portion; 
 a lift structure configured to actuate vertically along the lift post; 
 a second lift post; 
 a second lift structure configured to actuate vertically along the second lift post; 
 a non-user-interface control assembly located at the upper portion of the lift post, the non-user-interface comprising:
 a motor operable to raise the lift structure, and 
 a variable frequency drive configured to alter a power provided by the motor based on a measurement; and 
 
 a user-interface control assembly located at the lower portion of the lift post, wherein the user-interface control assembly is configured to activate the motor, wherein the user-interface control assembly comprises a first pendant, wherein the first pendant comprises a magnet configured to selectively couple the first pendant to the first lift post or the second lift post. 
 
     
     
       2. The lift system of  claim 1 , wherein the user-interface control assembly is configured to operate on an electrical input voltage at or under 50 volts. 
     
     
       3. The lift system of  claim 1 , wherein the user-interface control assembly comprises a remote menu screen, wherein the variable frequency drive is in communication with the remote menu screen. 
     
     
       4. The lift system of  claim 1 , wherein the measurement comprises a load on the motor. 
     
     
       5. The lift system of  claim 1 , wherein the measurement comprises a current on the motor. 
     
     
       6. The lift system of  claim 1 , wherein the user-interface control assembly comprises a first pendant. 
     
     
       7. The lift system of  claim 6 , wherein the lift system further comprises a second lift post and a second lift structure. 
     
     
       8. The lift system of  claim 7 , wherein the user-interface control assembly comprises a second pendant coupled to the second lift post. 
     
     
       9. The lift system of  claim 8 , wherein the first pendant and the second dependent both comprises a retractile coil. 
     
     
       10. The lift system of  claim 8 , wherein the first pendant and the second dependent both comprise a magnet configured to selectively couple the first pendant and the second pendant to the first lift post and the second lift post, respectively. 
     
     
       11. The lift system of  claim 8 , wherein the first pendant and the second pendant are wired in series. 
     
     
       12. The lift system for  1 , wherein the non-user-interface further comprises a hydraulic reservoir and a float switch. 
     
     
       13. The lift system of  claim 12 , wherein the float switch is configured to determine in hydraulic fluid in the hydraulic reservoir is below a predetermined threshold. 
     
     
       14. The lift system of  claim 1 , wherein the user-interface control assembly comprises an emergency stop. 
     
     
       15. The lift system of  claim 1 , wherein the user-interface control assembly comprises an indicator light. 
     
     
       16. The lift system of  claim 1 , wherein the user-interface control assembly is in communication with the non-user-interface control assembly via a cable. 
     
     
       17. A lift system, comprising:
 a lift post, wherein the lift post comprises a lower portion and an upper portion; 
 a lift structure configured to actuate vertically along the lift post; 
 a non-user-interface control assembly located at the upper portion of the lift post, the non-user-interface comprising:
 a motor operable to raise the lift structure at a default raising speed, 
 a hydraulic reservoir, 
 a float switch configured to determine when fluid within the hydraulic reservoir is below a predetermined threshold, and 
 a variable frequency drive configured to alter a power provided by the motor to raise the lift structure at a second raising speed based on a measurement, 
 wherein the second raising speed is faster than the default raising speed; and 
 
 a user-interface control assembly located at the lower portion of the lift post, wherein the user-interface control assembly is configured to selectively activate the motor to raise the lift structure at the default raising speed, wherein the user-interface control assembly is further configured to selectively activate the motor to raise the lift structure at the second raising speed. 
 
     
     
       18. The lift system of  claim 17 , wherein the float switch is in communication with the variable frequency drive. 
     
     
       19. The lift system of  claim 18 , wherein the variable frequency drive comprises a processor. 
     
     
       20. A lift system, comprising:
 a lift post assembly, wherein the lift post assembly comprises a first post and a second post extending between a lower portion and an upper portion; 
 a lift structure assembly configured to actuate vertically along the lift post; 
 a non-user-interface control assembly located at the upper portion of the lift post, the non-user-interface comprising:
 a motor operable to raise the lift structure, and 
 a variable frequency drive configured to alter a power provided by the motor based on a measurement; and 
 
 a user-interface control assembly located at the lower portion of the lift post assembly, wherein the user-interface control assembly is configured to activate the motor, wherein the user-interface control assembly comprises a first pendant having a first button and a second pendant having a second button, wherein the first button and the second button must be simultaneously activated in order for the first button and the second button to activate the motor in a first lift mode.